When you change from one template to another everything is not going to preview perfectly, nor is it assigned by any form of automation. It can't be.

Not all modules and positions you have used in one template are necessarily named the same or positioned the same from that template to another. The same goes for the styling.

As an example; There is no way for Joomla! to know that you want your "Breadcrumbs" to be assigned to the new Akiraka Breadcrumbs-Bottom module position without you assigning the Breadcrumbs to that position. Unless of course, the position you had them assigned to before was named the same.

To begin you should open EXTENSIONS > TEMPLATE manager and assign any needed parameters within your new template.

Next I would open each module and assign the new positions within your new template accordingly.

You will need to do the same with your articles and any and all module suffixes you have assigned previously.

Changes and or new assignments may also be needed in your menu structure.

Module Variations: The same applies here. The module variation suffixes for Akiraka are not named or positioned the same as modules and module variations in Hivemind.

It sounds worse than it is. I've done this before... it just takes a bit of organizing and a little time.

The CHOICE of how you do this and if you do this is yours. If you have a smaller site with little content it may be quicker and more efficient to start fresh. Backup your data first and make some screen shots of how you had it before so you won't have to go completely go by memory.

Though I am sure this is not what you wanted to hear, I do hope this at least helps you to get started and helps you understand what is going on.